1. Field of the Invention
The present invention relates in general to the field of railroad maintenance. More particularly, the present invention relates to a vehicle that dispenses a chemical solution into spike holes of railroad ties during track maintenance.
2. Discussion of the Related Art
Rail anchors, used to secure a rail to railroad ties, typically are held in place by spikes driven into the ties. These spikes are removed during a variety of maintenance operations such as a rail re-lay or rail changeover operation, which results in the removal of the rail, the spikes that hold the tie plates to the ties, and tie plates associated therewith and also with the replacement of the rails. As a result of the pulling of the spikes that hold the rails to their plates, several holes remain in the tie at the location vacated by the plate. It is usually desirable to plug these “spike holes” to prevent rot and water freezing in the open spike holes from causing damage to the tie. In addition, should a spike be inserted into an existing spike hole, something of a substance should be in the location to retain the hold-down force of the spike within the tie.
The classic approach to plugging spike holes was simply to manually insert cedar plugs into the holes as part of the rail re-lay operation. These plugs initially were inserted by laborers walking along the railway. Later, machines were developed that permitted riding operators to insert plugs using hand-held tools.
More recently, several different chemical solutions have been developed that are injected into the holes and then react either with a component of the injected material, chemical, or water to form a relatively hard substance that approximates the physical characteristics of wood. Examples of such solutions include a polyurethane-based chemical, an epoxy-based chemical, and a water-based chemical. The first way of injecting these materials was to manually inject the solution into the spike holes using a caulk gun type device or “gun” that simultaneously mixes the constituent chemicals of the solution and injects the solution into the spike holes. This technique is still in use but generally is limited to relatively small-scale applications such as replacing a short section of railway.
Vehicles have been developed permitting riding operators to manually inject solution into spike holes using guns of the type historically used by walking operators but supplied with chemicals via one or more on-board tanks rather than a self-contained cartridge on the gun. The machine may be either self-propelled and move along the rails or mounted on the back of a pickup truck or the like. They typically include a single gun that is manually directed and activated by an operator. Other than being transported by a vehicle and having tanks, these types of devices are, in essence, the same as the traditional caulk gun style operation.
In all of these machines, the guns are controlled, manipulated and triggered by operator rather than being mounted on a work head and operated automatically. In addition, each of these prior machines or techniques required a dedicated operator to each gun rather than permitting a single operator to operate multiple guns.